Applications of Logic Programming In Language Analysis - Document Reconstruction From Existing Code

This paper describes the experience of researchers at the University of Naples, over many years, in the application of Logic Programming (LP), to software engineering topics. In particular, the authors have experimented with LP in order to facilitate the activities related to the reconstruction of part(s) of documentation, from existing code. For this reason, a tool called ''Language Analyser'' (Lan}An) has been implemented, which is able to analyse different programming languages. This tool is supported by a methodology based on logic and is able to analyse existing code, by extracting and abstracting information useful for building up documentation. Currently, Lan}An can reconstruct low-level documentation design such as nesting trees, algebraic forms, and high-level documentation design such as structure charts. These documents represent a basis on which to deal with the activities of comprehension, reuse, reengineering, and maintenance of existing code. Moreover, all documents can be seen in a graphical way by the use of a browsing tool, which enables a user to go through the reconstructed documentation. Lan}An has been implemented in Turbo PROLOG V.2.0. The latest version of Lan}An works on a PC (IBM-DOS), and analyses programming languages such as FORTRAN 77, ANSI C/Turbo C and PL/1